scholarly journals Evaluation of optical particulate matter sensors under realistic conditions of strong and mild urban pollution

2020 ◽  
Vol 13 (12) ◽  
pp. 6427-6443
Author(s):  
Adnan Masic ◽  
Dzevad Bibic ◽  
Boran Pikula ◽  
Almir Blazevic ◽  
Jasna Huremovic ◽  
...  

Abstract. In this paper we evaluate characteristics of three optical particulate matter sensors/sizers (OPS): high-end spectrometer 11-D (Grimm, Germany), low-cost sensor OPC-N2 (Alphasense, United Kingdom) and in-house developed MAQS (Mobile Air Quality System), which is based on another low-cost sensor – PMS5003 (Plantower, China), under realistic conditions of strong and mild urban pollution. Results were compared against a reference gravimetric system, based on a Gemini (Dadolab, Italy), 2.3 m3 h−1 air sampler, with two channels (simultaneously measuring PM2.5 and PM10 concentrations). The measurements were performed in Sarajevo, the capital of Bosnia-Herzegovina, from December 2019 until May 2020. This interval is divided into period 1 – strong pollution – and period 2 – mild pollution. The city of Sarajevo is one of the most polluted cities in Europe in terms of particulate matter: the average concentration of PM2.5 during the period 1 was 83 µg m−3, with daily average values exceeding 500 µg m−3. During period 2, the average concentration of PM2.5 was 20 µg m−3. These conditions represent a good opportunity to test optical devices against the reference instrument in a wide range of ambient particulate matter (PM) concentrations. The effect of an in-house developed diffusion dryer for 11-D is discussed as well. In order to analyse the mass distribution of particles, a scanning mobility particle sizer (SMPS), which together with the 11-D spectrometer gives the full spectrum from nanoparticles of diameter 10 nm to coarse particles of diameter 35 µm, was used. All tested devices showed excellent correlation with the reference instrument in period 1, with R2 values between 0.90 and 0.99 for daily average PM concentrations. However, in period 2, where the range of concentrations was much narrower, R2 values decreased significantly, to values from 0.28 to 0.92. We have also included results of a 13.5-month long-term comparison of our MAQS sensor with a nearby beta attenuation monitor (BAM) 1020 (Met One Instruments, USA) operated by the United States Environmental Protection Agency (US EPA), which showed similar correlation and no observable change in performance over time.

2020 ◽  
Author(s):  
Adnan Masic ◽  
Dzevad Bibic ◽  
Boran Pikula ◽  
Almir Blazevic ◽  
Jasna Huremovic ◽  
...  

Abstract. In this paper we evaluate characteristics of three optical particulate matter sensors/sizers (OPS): high-end spectrometer 11-D (Grimm, Germany), low-cost sensor OPC-N2 (Alphasense, United Kingdom) and in-house developed MAQS which is based on another low-cost sensor – PMS5003 (Plantower, China), under realistic conditions of strong and mild urban pollution. Results were compared against a reference gravimetric system, based on Gemini (Dadolab, Italy), 2.3 m3/h air sampler, with two channels (simultaneously measuring PM2.5 and PM10 concentrations). The measurements were performed in Sarajevo, the capital of Bosnia-Herzegovina, from December 2019 until May 2020. This interval is divided into period 1 – strong pollution (December 2019–March 2020) and period 2 – mild pollution (March 2020–May 2020). The city of Sarajevo is one of the most polluted cities in Europe in terms of aerosols: the average concentration of PM2.5 during the period 1 was 83 μg/m3, with daily aveverage values exceeding 500 μg/m3. During period 2, the average concentration of PM2.5 was 20 μg/m3. These conditions represent a good opportunity to test optical devices against reference instrument in a wide range of ambient particulate matter (PM) concentrations. The effect of an in-house developed diffusion dryer for 11-D is discussed as well. In order to analyze the mass distribution of aerosols, a scanning mobility particle sizer (SMPS) spectrometer, which together with the 11-D spectrometer gives the full spectrum from nanoparticles of diameter 10 nm to coarse particles of diameter 35 μm, was used. All tested devices showed excellent correlation with the reference instrument in period 1, with R2 values between 0.90 and 0.99 for daily average PM concentrations. However, in period 2, where the range of concentrations was much narrower, R2 values decreased significantly, to values from 0.28 to 0.92. We have also included results of a 13.5 month long-term comparison of our MAQS sensor with a nearby beta attenuation monitor (BAM) 1020 (Met One Instruments, USA) operated by the United States Environmental Protection Agency (US EPA), which showed similar correlation and no observable change of performance over time.


2020 ◽  
Vol 13 (10) ◽  
pp. 5319-5334
Author(s):  
Priyanka deSouza ◽  
Ralph A. Kahn ◽  
James A. Limbacher ◽  
Eloise A. Marais ◽  
Fábio Duarte ◽  
...  

Abstract. Poor air quality is the world's single largest environmental health risk, and air quality monitoring is crucial for developing informed air quality policies. Efforts to monitor air pollution in different countries are uneven, largely due to the high capital costs of reference air quality monitors (AQMs), especially for airborne particulate matter (PM). In sub-Saharan Africa, for example, few cities operate AQM systems. It is thus important to examine the potential of alternative monitoring approaches. Although PM measurements can be obtained from low-cost optical particle counters (OPCs), data quality can be an issue. This paper develops a new method using raw aerosol size distributions from multiple, surface-based low-cost OPCs to constrain the Multiangle Imaging SpectroRadiometer (MISR) component-specific, column aerosol optical depth (AOD) data, which contain some particle-size-resolved information. The combination allows us to derive surface aerosol concentrations for particles as small as ∼0.1 µm in diameter, which MISR detects but are below the OPC detection limit of ∼0.5 µm. As such, we obtain better constraints on the near-surface particulate matter (PM) concentration, especially as the smaller particles tend to dominate urban pollution. We test our method using data from five low-cost OPCs deployed in the city of Nairobi, Kenya, from 1 May 2016 to 2 March 2017. As MISR passes over Nairobi only once in about 8 d, we use the size-resolved MISR AODs to scale the more frequent Moderate Resolution Imaging Spectrometer (MODIS)-derived AODs over our sites. The size distribution derived from MISR and MODIS agrees well with that from the OPCs in the size range where the data overlap (adjusted-R2∼0.80). We then calculate surface-PM concentration from the combined data. The situation for this first demonstration of the technique had significant limitations. We thus identify factors that will reduce the uncertainty in this approach for future experiments. Within these constraints, the approach has the potential to greatly expand the range of cities that can afford to monitor long-term air quality trends and help inform public policy.


2020 ◽  
Author(s):  
Priyanka deSouza ◽  
Ralph A. Kahn ◽  
James A. Limbacher ◽  
Eloise A. Marais ◽  
Fábio Duarte ◽  
...  

Abstract. Poor air quality is the world’s single largest environmental health risk, and air quality monitoring is crucial for developing informed air quality policies. Efforts to monitor air pollution in different countries are uneven, largely due to the high capital costs of reference air quality monitors (AQMs), especially for airborne particulate matter (PM). In sub-Saharan Africa, for example, few cities operate AQM systems. It is thus important to examine the potential of alternative monitoring approaches. Although PM measurements can be obtained from low-cost optical particle counters (OPCs), data quality can be an issue. This paper develops a new method using raw aerosol size distributions from multiple, surface-based low-cost Optical Particle Counters (OPCs) to calibrate the Multi-angle Imaging SpectroRadiometer (MISR) component-specific, column aerosol optical depth (AOD) data, that contain some particle-size-resolved information. The combination allows us to derive surface aerosol concentrations for particles as small as ~ 0.1 μm in diameter that MISR detects but are below the OPC detection limit of ~ 0.5 μm. As such, we obtain better constraints on the near-surface particulate matter (PM) concentration, especially as the smaller particles tend to dominate urban pollution. We test our method using data from five low-cost OPCs deployed in the city of Nairobi, Kenya, from May 1 2016 to March 2 2017. As MISR passes over Nairobi only once in about eight days, we use the size-resolved MISR AODs to scale the more frequent Moderate Resolution Imaging Spectrometer (MODIS)-derived AODs over our sites. The size distribution derived from MISR and MODIS agrees well with that from the OPCs in the size range where the data overlap (adjusted-R2 ~ 0.80). We then calculate surface-PM concentration from the combined data. The situation for this first demonstration of the technique had significant limitations. We thus identify factors that will reduce the uncertainty in this approach for future experiments. Within these constraints, the approach has the potential to greatly expand the range of cities that can afford to monitor long-term air quality trends and help inform public policy.


Author(s):  
Juris Soms ◽  
Haralds Soms

The harmful health effects of airborne particulate matter (PM) pollutants are well-known. However, the spatial coverage of automated air quality observation stations of Latvian Environment, Geology and Meteorology Centre (LEGMC) is sparse. Therefore the capability for PM concentration detection was examined by using the low-cost optical PM sensor to improve the spatial resolution of environmental data. The aim of the study was to perform 24h/7d measurements of PM2.5 and PM10 concentrations during a period of one year and to identify air quality in Esplanāde housing estate, Daugavpils city. For data obtaining on the concentration of PM2.5 and PM10 particles measurements have been performed by optical sensor Nova SDS011; meteorological data were obtained using the database of LEGMC; for processing, analysis and visualization of obtained data statistical methods were applied. Evaluation of PM2.5 and PM10 daily average concentration variability in 2020 indicates that air quality in the urban environment could be assessed as good. A well-expressed statistical correlation between meteorological factors (t°C, relative humidity) and the average concentration of PM particles was not found. It highlights the necessity of further research.


2020 ◽  
Vol 29 (2) ◽  
pp. 741-759
Author(s):  
Ashley Ramsey ◽  
Margaret Lehman Blake

Purpose Limited evidence exists to guide the assessment and treatment of cognitive-communication disorders associated with right hemisphere stroke. The purpose of this study was to obtain information about speech-language pathologists' (SLPs') clinical practices and decision making for this population to understand what practices are being used and identify gaps in clinical practice. Method A survey was distributed via online ASHA Communities for the Special Interest Groups and other social media platforms. Respondents included 143 SLPs from across the United States representing 3–50 years of experience and a wide range of practice settings. Survey questions probed assessment practices including how tests are selected, what tests are used to diagnose specific deficits, and how confident SLPs were in their diagnoses. Treatment decisions were queried for a small set of disorders. Results SLPs routinely assess cognitive disorders using standardized tests. Communication disorders are less likely to be formally assessed. Three core right cerebral hemisphere deficits—anosognosia, aprosodia, and pragmatic deficits—are either not assessed or assessed only through observation by 80% of SLPs. Evidence-based treatments are commonly used for disorders of attention, awareness, and aprosodia. Conclusion Communication disorders are less likely to be formally assessed than cognitive disorders, creating a critical gap in care that cannot be filled by other allied health professionals. Suggestions for free or low-cost resources for evaluating pragmatics, prosody, and awareness are provided to aid SLPs in filling this gap. Supplemental Material https://doi.org/10.23641/asha.12159597


2021 ◽  
Vol 14 (3) ◽  
pp. 73-81
Author(s):  
Guo Peng ◽  
A. B. Umarova ◽  
G. S. Bykova

Currently, Beijing is facing increasing serious air quality problems. Atmospheric pollutants in Beijing are mainly composed of particulate matter, which is a key factor leading to adverse effects on human health. This paper uses hourly data from 36 environmental monitoring stations in Beijing from 2015 to 2020 to obtain the temporal and spatial distribution of the mass concentration of particulate matter with a diameter smaller than 2.5 μm (PM2.5). The 36 stations established by the Ministry of Ecology and Environment and the Beijing Environmental Protection Monitoring Center and obtain continuous real-time monitoring of particulate matter. And the 36 stations are divided into 13 main urban environmental assessment points, 11 suburban assessment points, 1 control point, 6 district assessment points, and 5 traffic pollution monitoring points. The annual average concentration of PM2.5 in Beijing was 60 μg/m3 with a negative trend of approximately 14% year-1. In urban areas the annual average concentration of PM2.5 was 59 μg/m3, in suburbs 56 μg/m3, in traffic areas 63 μg/m3, and in district areas 62 μg/m3. From 2015 to 2020, in urban areas PM2.5 decreased by 14% year-1, in suburbs by 15% year -1, in traffic areas by 15% year-1, and in district areas by 12% year-1. The quarterly average concentrations of PM2.5 in winter andspring are higher than those in summer and autumn (64 μg/m3, 59 μg/m3, 45 μg/m3, 55 μg/m3, respectively). The influenceof meteorological factors on the daily average value of PM2.5 in each season was analysed. The daily average PM2.5 in spring, summer, autumn and winter is significantly negatively correlated with daily average wind speed, sunshine hours, and air pressure, and significantly positively correlated with daily average rainfall and relative humidity. Except for autumn, the daily average PM2.5 is positively correlated with temperature. Although Beijing’s PM2.5 has been declining since the adoption of the‘Air Pollution Prevention and Control Action Plan’, it is still far from the first level of the new ‘Ambient Air Quality Standard’(GB309S-2012) formulated by China in 2012.


2020 ◽  
pp. 17-19
Author(s):  
Nadiia DULHEROVA ◽  
Vlasta SHVAHIREVA

The paper is devoted to the study of e-commerce as an innovative way to implement a wide range of commercial relations remotely, and the readiness of the legal framework of the international community and Ukraine in particular to abandon traditional forms of doing business in favor of its digitalization. The paper examines US e-commerce law as a reference example of the progressive legal field of relationships emerging on the Internet. The paper reveals the key stages of development of e-commerce and the implementation of commercial relations in general. The paper also considers the regulations of governing the main aspects of e-commerce. The paper pays special attention to the analysis of the identification of obstacles and readiness of the international and Ukrainian legal framework for the formation of a safe environment for the free implementation of e-commerce. Аs the role of e-commerce in international trade is significant. In some countries, it reaches more than 50% of all purchases (for example, the United States and the United Kingdom). The future of international trade is closely linked to the development of e-commerce, as its advantages are obvious over traditional forms of trade. Evidence of this can be the forecasts of analysts. E-commerce in international trade today plays an important role, as the Internet has become an effective intermediary between merchants around the world. International transactions in goods and services have been transformed throughout the supply chain. E-commerce is a major driver of economic growth in both developed and developing countries. The low cost of concluding contracts on the Internet allows companies of all sizes to expand their sales abroad and look for suppliers through Internet commerce. But the integration of information and communication technologies (ICT) into international business operations provides new opportunities and new challenges for businesses, governments, consumers and international organizations.


Author(s):  
Tim Rutherford-Johnson

By the start of the 21st century many of the foundations of postwar culture had disappeared: Europe had been rebuilt and, as the EU, had become one of the world’s largest economies; the United States’ claim to global dominance was threatened; and the postwar social democratic consensus was being replaced by market-led neoliberalism. Most importantly of all, the Cold War was over, and the World Wide Web had been born. Music After The Fall considers contemporary musical composition against this changed backdrop, placing it in the context of globalization, digitization, and new media. Drawing on theories from the other arts, in particular art and architecture, it expands the definition of Western art music to include forms of composition, experimental music, sound art, and crossover work from across the spectrum, inside and beyond the concert hall. Each chapter considers a wide range of composers, performers, works, and institutions are considered critically to build up a broad and rich picture of the new music ecosystem, from North American string quartets to Lebanese improvisers, from South American electroacoustic studios to pianos in the Australian outback. A new approach to the study of contemporary music is developed that relies less on taxonomies of style and technique, and more on the comparison of different responses to common themes, among them permission, fluidity, excess, and loss.


Author(s):  
Kathryn A. Sloan

Popular culture has long conflated Mexico with the macabre. Some persuasive intellectuals argue that Mexicans have a special relationship with death, formed in the crucible of their hybrid Aztec-European heritage. Death is their intimate friend; death is mocked and accepted with irony and fatalistic abandon. The commonplace nature of death desensitizes Mexicans to suffering. Death, simply put, defines Mexico. There must have been historical actors who looked away from human misery, but to essentialize a diverse group of people as possessing a unique death cult delights those who want to see the exotic in Mexico or distinguish that society from its peers. Examining tragic and untimely death—namely self-annihilation—reveals a counter narrative. What could be more chilling than suicide, especially the violent death of the young? What desperation or madness pushed the victim to raise the gun to the temple or slip the noose around the neck? A close examination of a wide range of twentieth-century historical documents proves that Mexicans did not accept death with a cavalier chuckle nor develop a unique death cult, for that matter. Quite the reverse, Mexicans behaved just as their contemporaries did in Austria, France, England, and the United States. They devoted scientific inquiry to the malady and mourned the loss of each life to suicide.


Author(s):  
David Vogel

This book examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990 global regulatory leadership has shifted to Europe. What explains this striking reversal? This book takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. The book traces how concerns over such risks—and pressure on political leaders to do something about them—have risen among the European public but declined among Americans. The book explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.


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